Endotracheal tube apparatus

Abstract

An apparatus for monitoring EMG signals of a patient's laryngeal muscles includes an endotracheal tube having an exterior surface and a first location configured to be positioned at the patient's vocal folds. A first electrode is formed on the exterior surface of the endotracheal tube substantially below the first location to receive EMG signals primarily from below the vocal folds. A second electrode is formed on the exterior surface of the endotracheal tube substantially above the first location to receive EMG signals primarily from above the vocal folds. The first and second electrodes are configured to receive the EMG signals from the laryngeal muscles when the endotracheal tube is placed in a trachea of the patient.

What is claimed is: 
     
       1. An apparatus for monitoring EMG signals of a patient's laryngeal muscles, comprising: an endotracheal tube having a tubular shaped exterior tube surface and a first location configured to be positioned at the patient's vocal folds; an inflatable cuff attached to the endotracheal tube; a first electrode formed on the exterior tube surface of the endotracheal tube substantially below the first location to receive EMG signals primarily from below the vocal folds; a second electrode formed on the exterior tube surface of the endotracheal tube substantially above the first location to receive EMG signals primarily from above the vocal folds, wherein the first and second electrodes are laterally and longitudinally offset from each other on the exterior tube surface of the endotracheal tube and configured to receive the EMG signals from the laryngeal muscles when the endotracheal tube is placed in a trachea of the patient; and at least one conductor coupled to the first and second electrodes to carry the EMG signals received by the electrodes to a processing apparatus. 
     
     
       2. The apparatus of  claim 1 , wherein the first electrode is formed on a posterior side of the endotracheal tube. 
     
     
       3. The apparatus of  claim 1 , wherein the second electrode is formed on an anterior side of the endotracheal tube. 
     
     
       4. The apparatus of  claim 1 , wherein the first electrode and the second electrode each have a length of about one inch. 
     
     
       5. The apparatus of  claim 1 , wherein each of the first electrode and the second electrode extends laterally around a circumference of the tube for a distance corresponding to an angle of about 60 degrees to 90 degrees. 
     
     
       6. The apparatus of  claim 1 , and further comprising:
 a third electrode formed on the exterior surface of the endotracheal tube substantially above the first location. 
 
     
     
       7. The apparatus of  claim 6 , wherein the first electrode is formed on a posterior side of the endotracheal tube, and the second and third electrodes are formed on an anterior side of the endotracheal tube. 
     
     
       8. The apparatus of  claim 1 , and further comprising:
 a third electrode formed on the exterior surface of the endotracheal tube substantially above the first location; and 
 a fourth electrode formed on the exterior surface of the endotracheal tube substantially below the first location. 
 
     
     
       9. The apparatus of  claim 8 , wherein the first and fourth electrodes are formed on a posterior side of the endotracheal tube, and the second and third electrodes are formed on an anterior side of the endotracheal tube. 
     
     
       10. A method of monitoring EMG signals of a patient's laryngeal muscles, comprising:
 providing an endotracheal tube having an exterior surface with electrodes formed thereon, wherein the endotracheal tube includes a first location configured to be positioned at the patient's vocal folds, and wherein the electrodes include a first electrode positioned substantially below the first location to receive EMG signals primarily from below the vocal folds and a second electrode positioned substantially above the first location to receive EMG signals primarily from above the vocal folds, and at least one tube placement marking positioned in an electrode region and configured to facilitate longitudinal and rotational positioning of the electrodes within a patient, wherein the at least one tube placement marking includes at least one band that substantially surrounds a circumference of the endotracheal tube, and a vertical line segment that extends in a longitudinal direction along the at least one band; sensing the EMG signals from the laryngeal muscles with the electrodes when the endotracheal tube is placed in a trachea of the patient; and outputting the EMG signals sensed by the conductive ink electrodes to a processing apparatus. 
 
     
     
       11. An apparatus for monitoring EMG signals of a patient's laryngeal muscles, comprising: an endotracheal tube having an exterior surface; laterally and longitudinally offset electrodes formed on the exterior surface in an electrode region of the endotracheal tube, the electrodes configured to receive the EMG signals from the laryngeal muscles when the endotracheal tube is placed in a trachea of the patient; at least one tube placement marking positioned in the electrode region and configured to facilitate longitudinal and rotational positioning of the electrodes within a patient, wherein the at least one tube placement marking includes at least one band that extends primarily in a lateral direction and substantially surrounds a circumference of the endotracheal tube, and a vertical line segment that extends primarily in a longitudinal direction along an entire longitudinal dimension of the at least one band; and at least one conductor coupled to electrodes to carry the EMG signals received by the electrodes to a processing apparatus. 
     
     
       12. The apparatus of  claim 11 , wherein the vertical line segment and the at least one band each have a length that is substantially the same as a length of the at least one electrode. 
     
     
       13. The apparatus of  claim 11 , wherein the at least one band comprises a plurality of solid color bands surrounding a circumference of the endotracheal tube. 
     
     
       14. The apparatus of  claim 13 , wherein the plurality of solid color bands includes three different colored bands. 
     
     
       15. The apparatus of  claim 11 , wherein the at least one tube placement marking further comprises a plurality of horizontal line segments that are each centered on the vertical line segment and are spaced apart from each other in the longitudinal direction. 
     
     
       16. The apparatus of  claim 11 , wherein the at least one tube placement marking further comprises first and second diagonal line segments that intersect each other at a common point and form an x-type marking. 
     
     
       17. The apparatus of  claim 16 , wherein the vertical line segment intersects the first and second diagonal line segments at the common point. 
     
     
       18. The apparatus of  claim 11 , wherein the at least one tube placement marking further comprises a first solid color triangular shaped marking and a second solid color triangular shaped marking. 
     
     
       19. The apparatus of  claim 11 , wherein the vertical line segment includes two solid color end portions separated by a solid color middle portion, and wherein the middle portion is formed of a color that is different than a color of the end portions. 
     
     
       20. An apparatus for monitoring EMG signals of a patient, comprising: an endotracheal tube having a tubular shaped exterior tube surface; only first, second, third, and fourth electrodes formed on the exterior tube surface of the endotracheal tube, wherein the first and fourth electrodes are laterally offset from each other and longitudinally aligned with each other on the exterior tube surface of the endotracheal tube and are configured to receive the EMG signals, wherein the second and third electrodes are laterally offset from each other and longitudinally aligned with each other on the exterior tube surface of the endotracheal tube and are configured to receive the EMG signals, and wherein the first and the fourth electrodes are longitudinally offset from the second and third electrodes; and at least one conductor coupled to the first, second, third, and fourth electrodes to carry the EMG signals received from the first, second, third, and fourth electrodes to a processing apparatus. 
     
     
       21. The apparatus of  claim 20 , wherein the first and fourth electrodes are configured to receive the EMG signals from laryngeal muscles in a posterior trachea of the patient, and wherein the second and third electrodes are configured to receive the EMG signals from laryngeal muscles in an anterior trachea of the patient. 
     
     
       22. The apparatus of  claim 20 , wherein the first and fourth electrodes receive the EMG signals primarily from below vocal folds of the patient, and the second and third electrodes receive the EMG signals primarily from above the vocal folds of the patient. 
     
     
       23. The apparatus of  claim 20 , wherein the first and fourth electrodes are positioned closer to a distal end of the endotracheal tube than the second and third electrodes. 
     
     
       24. The apparatus of  claim 20 , wherein each of the electrodes extends laterally around a circumference of the endotracheal tube for a distance corresponding to an angle of about 60 degrees to 90 degrees. 
     
     
       25. The apparatus of  claim 20 , wherein the electrodes are laterally spaced apart from each other around a circumference of the endotracheal tube by a distance corresponding to an angle of about 15 degrees to 30 degrees. 
     
     
       26. The apparatus of  claim 20 , wherein a proximal portion of the first and fourth electrodes longitudinally overlaps with a distal portion of the second and third electrodes. 
     
     
       27. The apparatus of  claim 26 , wherein the proximal portion of the first and fourth electrodes longitudinally overlaps with the distal portion of the second and third electrodes by a length of about 0.1 to 0.2 inches. 
     
     
       28. The apparatus of  claim 20 , wherein the first and fourth electrodes are positioned entirely on a posterior side of the endotracheal tube that is configured to be positioned along a posterior trachea of the patient, and wherein the second and third electrodes are positioned entirely on an anterior side of the endotracheal tube that is configured to be positioned along an anterior trachea of the patient. 
     
     
       29. The apparatus of  claim 28 , wherein the endotracheal tube further comprises a cuff inflating lumen formed in the anterior side of the endotracheal tube. 
     
     
       30. The apparatus of  claim 20 , wherein the electrodes each have a length of at least about one inch. 
     
     
       31. The apparatus of  claim 20 , and further comprising a tube placement marking positioned by the electrodes on an anterior side of the endotracheal tube and configured to facilitate longitudinal and rotational positioning of the electrodes within the patient, wherein the tube placement marking includes a band that extends primarily in a lateral direction and at least partially surrounds a circumference of the endotracheal tube, and a vertical line segment that extends primarily in a longitudinal direction along at least an entire longitudinal dimension of the at least one band. 
     
     
       32. The apparatus of  claim 31 , wherein the tube placement marking comprises a blue color that helps differentiate the tube placement marking from blood and surrounding tissue. 
     
     
       33. The apparatus of  claim 20 , wherein the electrodes provide 2 EMG channels. 
     
     
       34. The apparatus of  claim 20 , wherein the electrodes provide 4 EMG channels. 
     
     
       35. The apparatus of  claim 20 , wherein the electrodes provide 6 EMG channels. 
     
     
       36. The apparatus of  claim 20 , wherein the first and second electrodes are used for a first EMG channel, and the third and the fourth electrodes are used for a second EMG channel.